Chapter 18: Plastics, skin, and soft tissues. Flashcards
Skin: primarily cellular
Epidermis
Main cell type in epidermis; originate from basal layer; provide mechanical barrier
Keratinocytes
Neuroectodermal origin (neural crest cells); in basal cell layer of epidermis
Melanocytes
Have dendritic processes that transfer melanin to neighboring keratinocytes via melanosomes
Melanocytes
How do melanocytes differ among races?
Density of melanocytes is the same among races; difference is in melanin production
Skin: primarily structural proteins (collagen) for the epidermis
Dermis
- Acts as antigen-presenting cells (MHC Class II)
- Originate form bone marrow
- Have a role in contact hypersensitivity reactions (type 4)
Melanocytes
Sensory nerves: pressure
Pacinian corpuscles
Sensory nerves: warmth
Ruffini’s endings
Sensory nerves: cold
Krause’s end-bulbs
Sensory nerves: Meissner’s corpuscles
Tactile sense
Aqueous sweat (thermal regulation, usually hypotonic)
Eccrine sweat glands
Milky sweat
- highest concentration of glands in palms and soles
Apocrine sweat glands
What autonomic is in control of sweat production?
Most sweat is the result of sympathetic nervous system via acetylcholine
Drug type: increased skin absorption
Lipid-soluble drugs
Predominate collage type in skin; 70% of dermis; gives tensile strength
Type 1 Collagen
Resistance to stretching (collagen)
Tension
Ability to regain shape (branching proteins that can stretch to 2x normal length)
Elasticity
What causes Cushing’s striae?
Caused by loss of tensile strength and elasticity
MCC of pedicled or anastomosed free flap necrosis
Venous thrombosis
Flaps: what causes tissue expansion?
Occurs by local recruitment, thinning of the dermis and epidermis, mitosis
TRAM flaps: complications
Flap necrosis, ventral hernia, bleeding, infection, abdominal wall weakness
TRAM flaps: rely on what vessel?
Superior epigastric vessels
Most important determinant of TRAM flap viability?
Periumbilical perforators
What is a TRAM flap?
Transversus rectus abdominis flap
Stage I Pressure ulcer
Erythema and pain; no skin loss
Stage 2 Pressure Ulcer
- Treatment?
Partial skin loss with yellow debris
- Tx: local treatment, keep pressure off
Stage 3 Pressure Ulcer
- Treatment?
Full-thickness skin loss; subcutaneous fat exposure
- Tx: sharp debridement; likely need myocutaneous flap
Stage 4 Pressure Ulcer
- Treatment?
Involves bony cortex, muscle
- Tx: myocutaneous flap
- Damages DNA and repair mechanisms
- Both a promoter and initiator
UV radiation
Single best factor for protecting skin from UV radiation
Melanin
Responsible for chronic sun damage
UV-B
Represents only 5% of skin CA but accounts for 65% of the deaths
Melanoma
Risk factors for melanoma
- Dysplastic, atypical or large congenital nevi
- Familial BK mole syndrome
- Xeroderma pigmentosum
- Fair complexion, easy sunburn, intermittent sunburns, previous skin CA, previous XRT
10% lifetime risk for melanoma
Dysplastic, atypical, or large congenital nevi
Almost 100% risk of melanoma
Familial BK mole syndrome
% melanomas that are familial
10%
MC melanoma site on skin
Back in men, legs in women
What carries a worse prognosis in melanoma?
Men, ulcerated lesions, ocular and mucosal lesions
Signs of melanoma
- Asymmetry (angulations, indentation, notching, ulceration, bleeding)
- Borders that are irregular
- Color change (darkening)
- Diameter increase
- Evolving over time
Where does melanoma originate?
Originates from neural crest cells (melanocytes) in basal layer epidermis
Color: most ominous sign of melanoma
Blue color
MC location for distant melanoma metastases
Lung
Diagnosis melanoma:
- 2 cm lesion or cosmetically sensitive area
- 2cm or cosmetically sensitive area: incisional biopsy (or punch biopsy), will need to resect with margins if path shows melanoma
Five types of melanoma
- Melanoma in situ or thin lentigo maligna (Hutchinson’s freckle)
- Lentigo maligna melanoma
- Superficial spreading melanoma
- Nodular
- Acral lentiginous
Components of melanoma staging workup
Chest/abd/pelvic CT, LFTs, and LDH for all melanoma > 1mm; examine all possible draining lymph nodes
Melanoma: treatment for all stages
1) Resection of primary tumor with appropriate margins
- AND -
2) Management of lymph nodes
Surgical margins for melanoma excision:
- In situ (mm)
- 1.0 (mm)
- 1.1 - 2.0 (mm)
- > 2.0 (mm)
- In situ (mm): 0.5 - 1.0 cm
- 1.0 (mm): 1.0 cm
- 1.1 - 2.0 (mm): 1.0 - 2.0 cm
- > 2.0 (mm): 2.0 cm
Surgical margins for melanoma excision:
- In situ (mm)
- In situ (mm): 0.5 - 1.0 cm
Surgical margins for melanoma excision:
- 1.0 (mm)
- 1.0 (mm): 1.0 cm
Surgical margins for melanoma excision:
- 1.1 - 2.0 (mm)
- 1.1 - 2.0 (mm): 1.0 - 2.0 cm
Surgical margins for melanoma excision:
- > 2.0 (mm)
- > 2.0 (mm): 2.0 cm
Melanoma: what nodes do you need to resect?
Always need to resect clinically positive nodes
Melanoma: when do you perform sentinel lymph node biopsy?
If nodes clinically negative and tumor >/ 1 mm deep
Characteristic of involved nodes in melanoma
Involved nodes usually nontender, round, hard 1-2 cm
What do you need to include for all anterior head / neck melanomas >/ 1mm deep?
Superficial parotidectomy (20% metastasis rate to parotid)
Tx: axillary node melanoma with no other primary
Complete axillary node dissection (remove Level 1, 2 , and 3 nodes - unlike breast CA)
Melanoma: has provided some patients with long disease-free interval and is the best chance for cure
Resection of metastases
- Isolated metastases (ie lung or liver) that can be resected with a low-risk procedure should probably undergo resection
Melanoma: can be used for systemic disease
IL-2 and tumor vaccines
Most common malignancy in US
Basal cell carcinoma
- 4x more common than squamous cell skin cancer
- 80% on head and neck
What does basal cell carcinoma originate from?
Epidermis - basal epithelial cells and hair follicles
-Pearly appearance, rolled borders, slow and indolent growth
Basal cell carcinoma
Path: basal cell carcinoma
Peripheral palisading of nuclei and stromal retraction
Basal cell carcinoma: what do you do for clinically positive nodes
Regional adenectomy
Basal cell carcinoma: most aggressive, has collegians production
Morpheaform type
Basal cell carcinoma:
- Treatment: 0.3 - 0.5 cm margins
XRT and chemotherapy: may be of limited benefit for inoperable disease, mets or neuro/lymphatic/vessel invasion
- Overlying erythema, papulonodular with crust and ulceration; usually red-brown
- May have surrounding induration and satellite nodules
- Can develop in post-XRT areas or in old burn scars
Squamous cell carcinoma
Incidence of metastasis: squamous cell vs basal cell vs melanoma
Melanoma > squamous cell carcinoma > basal cell carcinoma
Risk factors for squamous cell carcinoma
Actinic keratoses, xeroderma pigmentosum, Bowen’s disease, atrophic epidermis, arsenics, hydrocarbons (coal tar), chlorophenols, HPV, immunosuppression, sun exposure, fair skin, previous XRT, previous skin cancer
Risk factors for metastasis in squamous cell carcinoma
Poorly differentiated, greater depth, recurrent lesions, immunosuppression
Squamous cell carcinoma - tx: 0.5 - 1.0 cm margins for low risk
- Can treat high risk with Mohs surgery when trying to minimize area of resection (i.e., lesions on facE)
- Regional adenectomy for clinically positive nodes
- XRT and chemotherapy - may be of limited benefit for inoperable disease, mets, or neuo/lymphatic/vessel invasion
Margin mapping using conservative slices; not used for melanoma
Mohs surgery
MC soft tissue sarcomas
- Malignant fibrous histiosarcoma
2. Liposarcoma
MC location / age of soft tissue sarcoma
50% arise from extremities; 50% in children (arise from embryonic mesoderm)
- Most are large, grow rapidly, painless
- Symptoms: asymptomatic mass (MC presentation), GIB, bowel obstruction, neurologic deficit
Soft tissue sarcoma
Imaging studies necessary for soft tissue sarcomas
- CXR: to r/o lung mets
- MRI before biopsy: to r/o vascular, neuro, or bone invasion
Soft tissue sarcoma: excisional biopsy vs longitudinal incisonal biopsy
- Excisional biopsy: mass 4cm
- Need to eventually resect biopsy skin site if biopsy shows sarcoma
MC site for mets of soft tissue sarcoma
Lung
How do mets spread in soft tissue sarcoma?
Hematogenous spread, not to lymphatics -> mets to nodes is rare
What is staging based on in soft tissue sarcoma?
Staging based on grade, not size
Tx: soft tissue sarcoma
Want at least 3-cm margins and at least 1 uninvolved fascial plane -> try to perform limb-sparing operating.
- Place clips to mark site of likely recurrence -> will XRT these later
Post op XRT: soft tissue sarcomas
For high-grade tumors, close margins, or tumors > 5 cm
Chemotherapy: soft tissue sarcoma
Chemotherapy is doxorubicin based
What to think about with soft tissue sarcomas and tumors > 10 cm?
Tumors > 10 cm may benefit from pre op chemo XRT -> may allow limb-sparing resection
Tx: isolated sarcoma metastases
Isolated sarcoma mets without other evidence of systemic disease can be resected and are the best chance for survival; otherwise can palliate with XRT
Incision favored for pelvic and retroperitoneal sarcomas
Midline incision
What do you try to preserve in resection of soft tissue sarcoma?
Try to preserve motor nerves and retain or reconstruct vessels.
Poor prognosis overall: soft tissue sarcoma
- Delay in diagnosis
- Difficulty with total resection
- Difficulty getting XRT to pelvic tumors
Survival rate with complete resection of soft tissue sarcoma
40% 5-year survival rate
Can occur in pediatric population (usually rhabdomyosarcoma)
Head and neck sarcomas
Why are head and neck sarcomas difficult to get margins?
Because of proximity to vital structures. Post op XRT for positive or close margins as negative margins may be impossible to obtain
Most commonly are leiomyosarcomas and liposarcomas
Visceral and retroperitoneal sarcoma
What is the most important prognostic factor in visceral and retroperitoneal sarcomas?
The ability to completely remove the tumor
Risk factors for soft tissue sarcoma
- Asbestos: mesothelioma
- PVC and arsenic: angiosarcoma
- Chronic lymphedema: lymphangiosarcoma
- Vascular sarcoma
- a/w immunocompromised state
Kaposi’s sarcoma
MC malignancy in AIDS
Kaposi’s sarcoma
- Rarely a cause of death in AIDS
MC site Kaposi’s sarcoma (vascular sarcoma)
Oral and pharyngeal mucosa (s/s: bleeding, dysphagia)
Tx: Kaposi’s sarcoma
- AIDS tx (HAART) shrinks AIDS-related KS (best tx)
- Consider XRT or intra-lesional vinblastine for local disease
- Interferon-alpha for disseminated disease
- Surgery for severe intestinal hemorrhage
Best treatment AIDS-related Kaposi sarcoma
AIDS Tx (HAART) shrinks it
Tx: local disease - Kaposi’s sarcoma
Consider XRT or intra-lesional vinblastine
Tx: disseminated disease - Kaposi’s sarcoma
Interferon-alpha
Tx: severe intestinal hemorrhage - Kaposi’s sarcoma
Surgery
1 soft tissue sarcoma in kids
Childhood rhabdomyosarcoma
Poorest prognosis in childhood rhabdomyosarcoma
Head/neck, genitourinary, extremities, and trunk
MC subtype childhood rhabdomyosarcoma
Embryonal
Worst prognosis childhood rhabdomyosarcoma
Alveolar
Tx: childhood rhabdomyosarcoma
Surgery; doxorubicin-based chemotherapy
Most are metastatic at the time of diagnosis
Osteosarcoma
- Increased incidence around the knee
- Originates from metaphyseal cells
- Usually in children
Osteosarcoma
CNS tumors
Peripheral sheath tumors
Pheochromocytoma
Neurofibromatosis
Childhood rhabdomyosarcoma, many others
Li-fraumeni syndrome
Also includes other sarcomas
Hereditary retinoblastoma
Angiomyolipoma is associated with what?
Tuberous sclerosis
Familial adenomatous polyposis and intra-abdominal desmoid tumors
Gardner’s syndrome
What is important in lip lacerations?
Lip lacerations: important to line up vermillion border
Yellow, contains histiocytes
- Tx: excision
Xanthoma
Viral origin, contagious, autoinoculable, can be painful
- Tx: liquid nitrogen initially
Warts (verruca vulgaris)
Can be associated with neurofibromatosis and von Recklinghausen’s disease (cafe-au-lait spots, axillary freckling, peripheral nerve and CNS tumors)
Neuromas
Café-Au-Lait spots, axillary freckling, peripheral nerve and CNS tumors
von Recklinghausen’s disease
Keratoses: Premalignant in sun-damaged areas; need excisional biopsy if suspicious
Actinic keratosis
Keratoses: Not premalignant; trunk on elderly, can be dark
Seborrheic keratosis
Keratoses: associated with squamous cell carcinoma
Arsenical keratoses
- Very aggressive malignant tumor with early regional and systemic spread
- Red to purple papulonodule or indurated plaque
Merkel cell carcinoma (are neuroendocrine)
Have neuron-specific enolase (NSE), cytokeratin, and neurofilamint protein
Merkel cell carcinoma (are neuroendocrine)
- Painful tumor composed of blood vessels and nerves
- Benign; most common in the terminal aspect of the digit
Glomus tumor
- Tx: tumor excision
Benign but locally very invasive; occur in fascial planes
Desmoid tumors
Most common location of desmoid tumors
Anterior abdominal wall
When can anterior abdominal wall desmoid tumors happen?
Can occur during or following pregnancy; can also occur after trauma or surgery
Associated with gardner’s syndrome and retroperitoneal fibrosis; often encases bowel, making it hard to get en bloc resection
Intra-abdominal desmoids
High risk of local recurrences; no distant spread
Desmoid tumor
Tx: desmoid tumors
Surgery if possible; chemotherapy (sulindac, tamoxifen) if vital structure involved or too much bowel would be taken (high risk of short bowel syndrome with surgery)
SCCA in situ; 10% turn into invasive SCCA; associated with HPV
Bowen’s disease
Tx: Bowen’s disease
Imiquimod, cautery ablation, topical 5-FU, avoid wide local excision if possible (high recurrence rate with HPV), regular biopsies to rule out cancer
- Rapid growth, rolled edges, crater filled with keratin
- is not malignant but can be confused with SCCA
- involutes spontaneously over months
Keratoacanthoma
Tx: keratoacanthoma
- Always biopsy these to be sure
- If small, excise; if large, biopsy and observe
Increased sweating, especially noticeable in the palms.
- Tx?
Hyperhidrosis
Tx: thoracic sympathectomy if refractory to variety of antiperspirants
Infection of apocrine sweat glands, usually in axilla and groin regions
- Staph / strep most common organisms
Hidradenitis
Tx: hidradenitis
Antibiotics, improved hygiene first; may need surgery to remove skin and associated sweat glands
Most common benign cysts
Epidermal inclusion cyst
- Have completely mature epidermis with creamy keratin material
Benign cyst: in scalp, no epidermis
Trichilemmal cyst
Benign cyst: over tendons, usually over wrist; filled with collagen material
Ganglion cyst
Benign cyst: midline intra-abdominal and sacral lesions usual; need resection due to malignancy risk
Dermoid cyst
Benign cyst: congenital coccygeal sinus with ingrown hair; gets infected and needs to be excised
Pilnoidal cyst
